PubReading [44] - I-motif DNA structures are formed in the nuclei of human cells - M. Zeraati, D. Christ et al.

<p>Human genome function is underpinned by the primary storage of genetic information in canonical B-form DNA, with a second layer of DNA structure providing regulatory control. <strong>I-motif structures</strong> are thought to form in <strong>cytosine-rich regions</strong> of the genome and to have regulatory functions; however, in vivo evidence for the existence of such structures has so far remained elusive. Here we report the generation and characterization of an antibody fragment (<strong>iMab</strong>) that recognizes i-motif structures with high selectivity and affinity, enabling the detection of i-motifs in the nuclei of human cells. We demonstrate that the in vivo formation of such structures is<strong> cell-cycle and pH dependent</strong>. Furthermore, we provide evidence that i-motif structures are formed in regulatory regions of the human genome, including promoters and telomeric regions. Our results support the notion that i-motif structures provide key regulatory roles in the genome. - doi.org/10.1038/s41557-018-0046-3 - 2018</p>